a) Field of the Invention
The present invention relates to a card reader which reads data on a magnetic card or a card similar to a magnetic card. More specifically, the present invention relates to a shutter mechanism for a card reader.
b) Description of the Related Art
There are two types of card readers, namely, motor type and manual type, and it has become essential that both types have a countermeasure for fraudulent insertion of a foreign material, except coins or bills.
Examples of such countermeasures include providing a card reader with a complete shutter provided at the card insertion port, a driving source such as a solenoid for opening or closing of the complete shutter, and a sensor for detecting insertion of a card into a card insertion port. In this card reader, a sensor detects a card being inserted, which actuates a solenoid, which in turn opens the complete shutter. When a card is not inserted, the complete shutter is closed to prevent the card insertion port from insertion of foreign material.
Alternately, a pre-head may be provided in place of the above sensor such that the pre-head can read data on a card to be inserted before insertion. In this type, the pre-head determines whether the card to be inserted is a valid card such that a solenoid is actuated only when a valid card is inserted: when an inserted object (foreign object) is not a valid card, the complete shutter closes to prevent the card insertion port from the foreign object.
Alternately, detection members may be provided at both ends of the card insertion port such that each of the detection members turns off or on a common photo-sensor in a card reader of this type. Each of the detection members is actuated upon insertion of a card, which is detected by a photo-sensor, followed by actuation of a solenoid to open the shutter.
Patent Publication 1: Japanese Laid-open Patent Application No. H11-85916 (See Japanese Patent Publication Official Gazette from page 6 (line 13 in the right column) to page 7 (line 6 in the left column)).
Problems the Invention Intends to Solve
In a card reader of the type in which a sensor detects a card, multiple sensors are required to enhance detection accuracy since a single sensor may erroneously detect a foreign object (e.g. bar) as a card. This increases the size and manufacturing cost of a card reader of this type.
In a card reader utilizing a pre-head, which usually is an expensive magnetic head, the pre-head must be arranged outside the shutter. This type also increases the size and manufacturing cost of a card reader of this type.
Further, in the card reader of the type in which detection members are provided at both ends of a card insertion port, a long arm must stretch from both ends of the card insertion port to a photo sensor, which also increases the size of the card reader.